This invention relates to a pressure coating roller assembly designed for use in roller coating by automatically feeding the coating material to the roller.
There are known and used generally various types of roller coating devices using a roller or rollers, the surface of which is covered with a layer of sponge, cloth, fur or other raised fabric material and impregnated with a coating material so as to spread the coating material on an object to be coated. For performing the coating operation at high efficiency in these types of coating devices, it is highly desirable to make an arrangement such that the coating material is automatically supplied to the roller to allow for a continuous coating operation.
For feed of the coating material in these types of roller coating system, there are generally employed the following two feed systems: an internal feed system in which the coating material is first supplied into the hollow inside of the roller and then passed through a plurality of small holes opening from the inside to the outside of the roller so that the coating material is impregnated in the external sponge or other roller surface layer, and an external feed system in which one or more coating material jet orifices are provided in opposition to the external surface of the roller and the coating material supplied under pressure is ejected from such orifices to the roller surface so that the coating material is impregnated in the sponge or other surface layer of the roller. In the former system, however, since the coating material is fed into the inside of the roller, the roller weight increases to an extent as to result in reduced workability. This system also involves the difficulty and trouble of cleaning the inside of the roller. In the latter system, on the other hand, difficulty is encountered in attaining uniform feed of the coating material to the roller surface. The conventional feed systems present the problems of nonuniform spreading and scattering of the coating material from the roller to soil the surrounding areas.